diff options
| author | Suren Baghdasaryan <surenb@google.com> | 2022-07-31 11:19:31 -0700 |
|---|---|---|
| committer | Suren Baghdasaryan <surenb@google.com> | 2024-02-19 02:58:25 +0000 |
| commit | 593bc4ea6aafbecb76fbf4e406b002f0764864ad (patch) | |
| tree | ac0105ea3e49222c13bdc7690325a396a32f2063 | |
| parent | b616ca340e5b6e03763516b3eee50b21298e7520 (diff) | |
mm: introduce __GFP_NO_OBJ_EXT flag to selectively prevent slabobj_ext creation
Introduce __GFP_NO_OBJ_EXT flag in order to prevent recursive allocations
when allocating slabobj_ext on a slab.
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
| -rw-r--r-- | include/linux/gfp_types.h | 11 | ||||
| -rw-r--r-- | mm/slub.c | 2 |
2 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h index 868c8fb1bbc1..e36e168d8cfd 100644 --- a/include/linux/gfp_types.h +++ b/include/linux/gfp_types.h @@ -53,6 +53,9 @@ enum { #ifdef CONFIG_LOCKDEP ___GFP_NOLOCKDEP_BIT, #endif +#ifdef CONFIG_SLAB_OBJ_EXT + ___GFP_NO_OBJ_EXT_BIT, +#endif ___GFP_LAST_BIT }; @@ -93,6 +96,11 @@ enum { #else #define ___GFP_NOLOCKDEP 0 #endif +#ifdef CONFIG_SLAB_OBJ_EXT +#define ___GFP_NO_OBJ_EXT BIT(___GFP_NO_OBJ_EXT_BIT) +#else +#define ___GFP_NO_OBJ_EXT 0 +#endif /* * Physical address zone modifiers (see linux/mmzone.h - low four bits) @@ -133,12 +141,15 @@ enum { * node with no fallbacks or placement policy enforcements. * * %__GFP_ACCOUNT causes the allocation to be accounted to kmemcg. + * + * %__GFP_NO_OBJ_EXT causes slab allocation to have no object extension. */ #define __GFP_RECLAIMABLE ((__force gfp_t)___GFP_RECLAIMABLE) #define __GFP_WRITE ((__force gfp_t)___GFP_WRITE) #define __GFP_HARDWALL ((__force gfp_t)___GFP_HARDWALL) #define __GFP_THISNODE ((__force gfp_t)___GFP_THISNODE) #define __GFP_ACCOUNT ((__force gfp_t)___GFP_ACCOUNT) +#define __GFP_NO_OBJ_EXT ((__force gfp_t)___GFP_NO_OBJ_EXT) /** * DOC: Watermark modifiers diff --git a/mm/slub.c b/mm/slub.c index 76fb600fbc80..ca803b2949fc 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1899,6 +1899,8 @@ int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, void *vec; gfp &= ~OBJCGS_CLEAR_MASK; + /* Prevent recursive extension vector allocation */ + gfp |= __GFP_NO_OBJ_EXT; vec = kcalloc_node(objects, sizeof(struct slabobj_ext), gfp, slab_nid(slab)); if (!vec) |